Well instrument positioning device

ABSTRACT

An apparatus is provided for positioning a well instrument in a well in the proper position for a well operation. An annular movable element is positioned encircling the well instrument housing. A movable arm is connected to the well instrument housing by a pivot that allows the movable arm to turn relative to said instrument housing. One end of the movable arm is linked to the annular movable element so that said end of the movable arm moves with the annular movable element. A spring encircles the well instrument housing and is connected between the well instrument housing and the annular movable element. A release element allows the force of the spring to move the annular movable element causing the movable arm to pivot and thereby extend the other end of the movable arm until it contacts the wall of the well and places the well instrument in the proper position for the desired well operation.

United States Patent Wolk Oct. 2, 1973 WELL INSTRUMENT POSITIONINGPrimary Examincr-David H. Brown DEVICE Attorney-Robert W. Mayer et al.

[75] Inventor: Piero Wolk, Houston, Tex.

[57] ABSTRACT [73] Assignee: Dresser Industries, Inc., Dallas, Tex.

An apparatus is provlded for positioning a well instru- I Filed: y 25,1972 ment in a well in the proper position for a well opera- [21 ApptNu: 274,939 tion. An annular movable element is positioned encirclingthe well instrument housing. A movable arm is connected to the wellinstrument housing by a pivot [52] US. Cl. 166/241, 175/452 that allowsthe movable arm t0 tum relative to said [51] Int. Cl E2lb 17/10, E2lb23/00 sttumeht housing o end f the movable arm is [58] Field of Search166/100, 55.1, 55.2, linked to the annular movable element so that Saidand 166/241; 175/451, 4.5 456 of the movable arm moves with the annularmovable element. A spring encircles the well instrument housing [56]Reiermces Cited and is connected between the well instrument housingUNITED STATES PATENTS and the annular movable element. A release element1,898,074 2 1933 Bailey 166/241 ux allows the force Ofthe Spring to movcthe annular 3.555,689 1/1971 Cubber|y.. 166/241 X able element causingthe movable arm to pivot and 3,064,571 11/1962 True 1661/55.] X therebyextend the other end of the movable arm until 3,087,552 4/I963 Grahaml66/24l X it contacts the wall of the we" and places the we" in.3,092,182 6/1963 Blagg 166/241 Strument in the proper position f thedesired we" 3,550,695 12/1970 Shore 175/456 X eration. 3,707,195 12/1972Lanmon 166/100 X 11 Claims, 3 Drawing Figures 3.762.473 SHEET 2 [IF 2PATENTED 2 1 WELL INSTRUMENT POSITIONING DEVICE BACKGROUND OF THEINVENTION The present invention relates to the art of petroleumexploration and production and, more particularly, to an apparatus forpositioning a well instrument in a well.

Many well instruments must be properly oriented in a well before beingactuated to perform the desired operation in the well. For example, aperforating apparatus such as that shown in U. S. Pat. No. 3,589,453 toA. A. Venghiattes patented June 29, 1971 operates best if the instrumentis centered in the well. On the other hand, a perforating apparatus suchas that shown in U. S. Pat. No. 3,620,314 to F. O. Bohn patented Nov.16, 1971 operates sufficiently if it is positioned against one wall ofthe well. Logging instruments such as the logging instrument shown in U.S. Pat. No. 3,321,627 to C. W. Tittle patented May 23, 1967 requireproper orientation in the well during the logging operation.

Most of the prior art positioning devices are large and take up more ofthe length of the well instrument than is desirable. In addition, manyof the prior art positioning devices are larger in diameter than isdesirable. The provision of a small and compact positioning device willallow the space within the well instrument to be used with greaterefficiency and economy and will allow the well instrument to operatemore efficiently and under a wider variety of conditions.

In many instances a well instrument positioning device must be adaptedto be controlled by purely mechanical elements because any attempt totransmit current along the logging cable that controls the wellinstrument results in the possiblity of the current accidentallyactuating systems within the well instrument or in other waysinterfering with the operation of the well instrument. For example, inthe case of a perforator, the use of an electric current to control thepositioning device includes a substantial risk because the current couldaccidentally detonate the perforator charges.

DESCRIPTION OF THE PRIOR ART In U. S. Pat. No. 2,832,421 to R. C. Bakerpatented Apr. 29, 1958, a centering apparatus for well bore conduits isshown. The apparatus includes a tubular body adapted to form a part of aconduit string, a plurality of leaf springs disposed incircumferentially spaced relation around the exterior of said body andmeans for confining the ends of th leaf springs proximate said body.

In U. S. Pat. No. 2,652,118 to W. W. Hartman et al patented Sept. 15,1953, a basket guide is shown. The basket guide includes upper and lowercollars spaced substantially apart from each other and adapted toembrace and slide along the pipe with outwardly bowed springs fastenedto said upper and lower collars to form a guide.

In U. S. Pat. No. 2,231,767 to A. J. Mason, Jr. patented Feb. 11, 1941,an open hole support is shown. The support includes a leg pivotallymounted on the housing and link means for swinging the leg into aposition where its outer end engages the wall of the hole to support thehousing. The outer end of the leg presents a substantial area engagingthe bore wall and holding the element against downward movement.

In U. S. Pat. No. 3,620,314 to F. O. Bohn patented Nov. 16, 1971, acombination bullet perforating gun and shaped charge perforator isshown. The perforator includes a centralizer means for contacting thewall of the well and placing the perforator in the proper position foroperation.

SUMMARY OF THE INVENTION The present invention provides an apparatus forpositioning a well instrument in a well. A movable element is positionedon the well instrument. A movable arm is connected to the wellinstrument by a pivot means that allows the movable arm to turn relativeto the well instrument. A linking means links one end of the movable armwith the movable element so that said end of said arm moves with saidmovable element. A force means is provided for applying a force to themovable element and a release means is provided for selectivelyconnecting and disconnecting the movable element to the well instrument.

The above and other features and advantages of the present inventionwill become apparent from a consideration of the following detaileddescription of the invention when taken in conjunction with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a well instrumentconstructed in accordance with the present invention positioned in awell.

FIG. 2 shows the well instrument of FIG. 1 positioned for operation.

FIG. 3 illustrates another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, a wellinstrument generally designated by the reference numeral 10 isillustrated positioned in a well 11. The well 11 may be cased, uncased,may contain one or more strings of tubing or may in general be any typeof borehole. The well instrument 10 includes an operating section 12.The operating section 12 in the embodiment shown includes a multiplicityof individual operating units 13. The operating units 13 are perforatorsadapted to be selectively fired through a casing or tubing within well11. It is to be understood that other operating units such as a sidewallsampling unit similar to that shown in U. S. Pat. No. 3,272,268 to A. J.Tricon et al patented Sept. 13, 1969 could be used in place of theperforator operating units 13. It will be appreciated that this type ofoperating units is preferably positioned against the wall of the well 11during the operating cycle.

The well instrument 10 is lowered into the well 11 by a cable 14. Thecable 14 contains an electrical conductor for transmitting current toselectively detonate the perforator guns 13. It will be appreciated thatan apparatus for positioning the well instrument 10 should be operatedby purely mechanical systems since the transmission of a current downthe cable 14 for operating the positioning system would present asubstantial danger of detonation of the perforator guns 13. It can alsobe appreciated that the positioning system should be simple, reliableand take up a minimum amount of space along the body of the wellinstrument 10.

The well instrument 10 includes sections 15 and 15! that form a portionof the body of the well instrument. A fixed ring 16 is firmly secured tosection 15 and a fixed ring 16' is firmly secured to the section 15'. Arotating ring 17 is positioned to encircle the outside of the section 15and a rotating ring 17! is positioned to encircle the outside of thesectionv 15'. A torque spring 18 encircles the section 15 and has oneend connected to the fixed ring 16 and the other end connected to therotating ring 17. A torque spring 18 encircles the section 15' and hasone end connected to the fixed ring 16 and the other end connected tothe rotating ring 17'. A centralizing arm 19 is connected to the section15 at a pivot point by a pin 20. The upper end 21 of the arm 19 fitswithin a notch 22 in the rotating ring 17. A hole 23 extends through therotating ring 17 and is adapted to receive a lock pin 24. A centralizingarm 19' is connected to the section 15' at a pivot point by a pin 20.The upper end 21' of the arm 19' fits within a notch 22' in the rotatingring 17'. A hole 23' extends through the rotating ring 17' and isadapted to receive a lock pin 24'.

The structural details of an apparatus constructed in accordance withthe present invention having been described, the operation of theapparatus will now be considered with reference to FIG. 2. The wellinstrument is lowered into well 11 by cable 14. The centralizing arms 19and 19, rotating rings 17 and 17' and springs 18 and 18' are in theposition shown in FIG. 1 with the arms 19 and 19' next to the sectionsand 15. When the well instrument 10 reaches the depth in the wellwherein a perforation is desired, it becomes necessary to move theoperating section 12 against the wall of the well 11. This is easilyaccomplished by removing the lock pins 24 and 24. The lock pins may beconstructed of a material such as a plug of salt that will dissolvegradually when exposed to fluid in the well bore or a plug of dry icethat will melt. With the lock pins 24 and 24' removed, the rotatingrings 17 and 17 are moved by force from the torque springs 18 and 18'.As the rotating rings 17 and 17 turn, the upper ends 21 and 21 of thecentralizing arms 19 and 19' are also moved since they fit within thenotches 22 and 22 in the rotating rings 17 and 17'. This causes thecentralizing arms 19 and 19' to rotate on pins and 20 and turn about thepivot point. The lower ends 25 and 25 of centralizing arms 19 and 19'contact the wall of the well 11 and move the operating section 12proximate the wall of the well 11. Current is transmitted down the cable14 to detonate one or more of the perforating guns 13. The wellinstrument 10 may easily be withdrawn from the well because the arms 19and 19' can move in and out to accommodate any constrictions in the well11.

Referring now to FIG. 3, another embodiment of a well instrumentpositioning apparatus of the present invention is shown. The wellinstrument positioning apparatus is mounted upon the upper portion of awell instrument designated by the reference numeral 26. The wellinstrument 26 is adapted to be suspended in a well or borehole (notshown) by a cable 27. The lower portion of the well instrument 26consists of an operating section 28. This operating section 28 mayinclude perforators, logging instruments or other well operatingsystems.

A fixed ring 29 is firmly secured to the upper portion of the wellinstrument 26. A rotating ring 30 is positioned below the fixed ring 29and adapted to encircle the well instrument 26. A torque spring 31encircles the well instrument 26 and is located between the fixed ring29 and the rotating ring 30. The torque spring 31 has one end connectedto the fixed ring 29 and the other end connected to the rotating ring30. Three individual, centralizing arms 32. 33 and 34 are connected tothe well instrument 26 at three individual rotating points. A pinconnects each of the arms to the well instrument 26 with one of the pins35 being shown in FIG. 3. The upper end of each of the arms 32, 33 and34 fits within a notch in the rotating ring 30. The upper end 36 of arm32 is shown positioned within a notch 37 in rotating ring 30. A hole 38extends through the rotating ring 30 and is adapted to receive a lockpin 39.

In operation, the well instrument 26 is lowered into a well (not shown)by the cable 27 until it reaches a location in the well wherein thedesired well operation is to be performed. The lock pin 39 is removedand the arms allowed to move to their open position as shown in FIG. 3.This may be accomplished by the lock pin 39 being constructed frommaterial that will dissolve or melt when exposed to the well fluids. Thelock pin 39 is inserted in the hole 38 holding the arms in the closedposition until the well instrument 26 is in the desired position foroperation. The well instrument 26 is allowed to remain in that positionfor a period of time until the lock pin 39 dissolves allowing the forceof spring 31 to rotate rotating ring 30 and move arms 32, 33 and 34 totheir extended position. In some instances, it may be desirable toremove the lock pin 39 at the surface before the well instrument isinserted into the well. The arms 32, 33 and 34 will slide along the wallof the well until the well instrument reaches the depth wherein the welloperation is to be performed. The arms 32, 33 and 34 will retain thewell instrument in a centralized position throughout the well operation.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An apparatus for positioning a well instrument in a well, comprising:

a movable element positioned on said well instrument, said movableelement substantially encircling said well instrument;

a movable arm positioned on said well instrument;

means for linking one end of said movable arm with said movable elementso that said end of said arm is adapted to move with said movableelement; and

force means for rotating said movable element relative to said wellinstrument.

2. The apparatus of claim 1 wherein said force means is a spring thatsubstantially encircles said well instrument with one end of said springconnected to said movable element and the other end of said springconnected to said well instrument.

3. The apparatus of claim 2 including at least one additional movablearm positioned on said well instrument and linking means for linking oneend of said additional movable arm with said movable element so thatsaid end of said arm is adapted to move with said movable element.

4. An apparatus for positioning a well instrument in a well, comprising:

a movable element positioned on said well instrument, said movableelement substantially encircling said well instrument;

a movable arm positioned on said well instrument;

means for linking one end of said movable arm with said movable elementso that said end of said arm is adapted to move with said movableelement;

at least one additional movable arm positioned on said well instrumentand linking means for linking one end of said additional movable armwith said movable element so that said end of said arm is adapted tomove with said movable element;

force means for applying a force to said movable element, said forcemeans being a spring that substantially encircles said well instrumentwith one end of said spring connected to said movable element and theother end of said spring connected to said well instrument; and

release means for selectively connecting and disconnecting said movableelement to said well instrument.

5. The apparatus of claim 4 wherein said release means is a pinconstructed of a material that will dissipate when exposed to theenvironmental conditions within the well.

6. The apparatus of claim 5 wherein said pin is constructed of salt.

7. The apparatus of claim 5 wherein said pin is constructed of dry ice.

8. An apparatus for positioning a well instrument in a well, comprising:

a movable element positioned around said well instrument, said movableelement substantially encircles said well instrument;

a movable arm;

pivot means for rotatably connecting said movable arm to said wellinstrument;

linking means for linking one end of said movable arm with said movableelement so that said end of said arm is adapted to move with saidmovable element; and

force means for rotating said movable element relative to said wellinstrument.

9. The apparatus of claim 8 wherein said force means is a spring thatsubstantially encircles said well instrument with one end of said springconnected to said movable element and the other end of said springconnected to said well instrument.

10. The apparatus of claim 8 including at least one additional movablearm, at least one additional pivot means for rotatably connecting saidadditional movable arm to said well instrument and at least oneadditional linking means for linking one end of said additional movablearm with said movable element so that said end of said arm is adapted tomove with said movable element.

11. An apparatus for positioning a well instrument in a well,comprising:

a movable element positioned around said well instrument, said movableelement substantially encircling said well instrument;

a movable arm;

pivot means for rotatably connecting said movable arm to said wellinstrument;

linking means for linking one end of said movable arm with said movableelement so that said end of said arm is adapted to move with saidmovable element;

force means for applying a force to said movable ele ment, said forcemeans being a spring that substantially encircles said well instrumentwith one end of said spring connected to said movable element and theother end of said spring connected to said well instrument; and

release means for selectively connecting and disconnecting said movableelement to said well instrument.

1. An apparatus for positioning a well instrument in a well, comprising:a movable element positioned on said well instrument, said movableelement substantially encircling said well instrument; a movable armpositioned on said well instrument; means for linking one end of saidmovable arm with said movable element so that said end of said arm isadapted to move with said movable element; and force means for rotatingsaid movable element relative to said well instrument.
 2. The apparatusof claim 1 wherein said force means is a spring that substantiallyencircles said well instrument with one end of said spring connected tosaid movable element and the other end of said spring connected to saidwell instrument.
 3. The apparatus of claim 2 including at least oneadditional movable arm positioned on said well instrument and linkingmeans for linking one end of said additional movable arm with saidmovable element so that said end of said arm is adapted to move withsaid movable element.
 4. An apparatus for positioning a well instrumentin a well, comprising: a movable element positioned on said wellinstrument, said movable element substantially encircling said wellinstrument; a movable arm positioned on said well instrument; means forlinking one end of said movable arm with said movable element so thatsaid end of said arm is adapted to move with said movable element; atleast one additional movable arm positioned on said well instrument andlinking means for linking one end of said additional movable arm withsaid movable element so that said end of said arm is adapted to movewith said movable element; force means for applying a force to saidmovable element, said force means being a spring that substantiallyencircles said well instrument with one end of said spring connected tosaid movable element and the other end of said spring connected to saidwell instrument; and release means for selectively connecting anddisconnecting said movable element to said well instrument.
 5. Theapparatus of claim 4 wherein said release means is a pin constructed ofa material that will dissipate when exposed to the environmentalconditions within the well.
 6. The apparatus of claim 5 wherein said pinis constructed of salt.
 7. The apparatus of claim 5 wherein said pin isconstructed of dry ice.
 8. An apparatus for positioning a wellinstrument in a well, comprising: a movable element positioned aroundsaid well instrument, said movable element substantially encircles saidwell instrument; a movable arm; pivot means for rotatably connectingsaid movable arm to said well instrument; linking means for linking oneend of said movable arm with said movable element so that said end ofsaid arm is adapted to move with said movable element; and force meansfor rotating said movable element relative to said well instrument. 9.The apparatus of claim 8 wherein said force means is a spring thatsubstantially encircles said well instrument with one end of said springconnected to said movable element and the other end of said springconnected to said well instrument.
 10. The apparatus of claim 8including at least one additional movable arm, at least one additionalpivot means for rotatably connecting said additional movable arm to saidwell instrument and at least one additional linking means for linkingone end of said additional movable arm with said movable element so thatsaid end of said arm is adapted to move with said movable element. 11.An apparatus for positioning a well instrument in a well, comprising: amovable element positioned around said well instrument, said movableelement substantially encircling said well instrument; a movable arm;pivot means for rotatably connecting said movable arm to said wellinstrument; linking means for linking one end of said movable arm withsaid movable element so that said end of said arm is adapted to movewith said movable element; force means for applying a force to saidmovable element, said force means being a spring that substantiallyencircles said well instrument with one end of said spring connected tosaid movable element and the other end of said spring connected to saidwell instrument; and release means for selectively connecting anddisconnecting said movable element to said well instrument.